A

Step 1: To determine which of the options is a form of energy, we need to analyze each term provided in the options.

Option A: Light - Light is a form of electromagnetic radiation and carries energy. This energy can be quantified in the context of photons and their interactions with matter. Thus, light is indeed a form of energy.

Option B: Pressure - Pressure is a measure of force per unit area. It is not a form of energy but rather a physical quantity related to the forces exerted by fluids.

Option C: Momentum - Momentum is a vector quantity defined as the product of an object's mass and its velocity. It is not energy but is related to motion.

Option D: Power - Power is the rate at which energy is transferred or converted. While related to energy, it is not a direct form of energy itself.

Conclusion: The correct answer is option A, as light is directly associated with energy.